XMM-Newton Essentials
The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations.

Since Earth's atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself.
Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.

Caught in the act: collision of two galaxy clusters ends almost deadly, 16-Jan-2015
Recent observations of the galaxy cluster RXCJ2359.5-6042 with the XMM-Newton space observatory reveal evidence for an ongoing merger that strips the smaller system of much of its gas.
Further details on
the MPE portal and on
National Geographic's pages.